Editing a local echo creates an invalid event that EX chokes on

[ara4n]

Steps to reproduce

1. Send messages while encryption is churning on EDR; everything gets head-of-line blocked.
2. Edit one of the messages.
3. On the EX side, it appears mangled:

Outcome

What did you expect?

Edits to local echos should not be corrupt

What happened instead?

Apparently they are.

Operating system

No response

Application version

nightly

How did you install the app?

No response

Homeserver

No response

Will you send logs?

No

[ara4n]

The edit in question here is:

    "decrypted": {
        "content": {
            "msgtype": "m.text",
            "body": " * and help unblock implementing unread-rooms (and accurate unread-notif counts)",
            "m.new_content": {
                "msgtype": "m.text",
                "body": "and help unblock implementing unread-rooms (and accurate unread-notif counts)",
                "m.mentions": {}
            },
            "m.mentions": {},
            "m.relates_to": {
                "rel_type": "m.replace",
                "event_id": "~!kCCQTCfnABLKGGvQjo:matrix.org:m1699715385559.77"
            }
        },
        "origin_server_ts": 1699715807450,
        "sender": "@matthew:matrix.org",
        "type": "m.room.message",
        "unsigned": {
            "age": 29548223,
            "transaction_id": "m1699715400921.79"
        },
        "event_id": "$0Cy8QyexJJvh6K7tIv3kcuD4T_du4z80d9nYd3SyZAE",
        "room_id": "!kCCQTCfnABLKGGvQjo:matrix.org"
    },

which looks pretty obviously mangled given it's trying to relate to a placeholder event ID (beginning with a ~).

[jplatte]

That error message (which probably shouldn't be visible directly in the timeline?) also makes no sense though, it's basically saying m.relates_to is empty, when it clearly isn't. Will investigate that when I get some time.

[t3chguy]

Only minor because another client choking on what is at best untrusted input is a major issue on their side